Various prosthetic liners are known in the prior art. For example, U.S. Pat. No. 5,446,443 (Wilson et al.) issued on Nov. 7, 1995 for a device characterized as PROSTHETIC DEVICE FOR AMPUTEES. That reference discusses the use of a prosthesis which has a relatively rigid, support shell dimensioned to receive a portion of the residual limb of the amputee. The apparatus also includes a pad member which has a plurality of pouches at least partially filled with fluid. It is intended that the pad member of that reference substantially encircle the residual portion of the amputee's leg with its fluid pouches being positioned adjacent one another about the end along the leg. The pad member having the pouches is, therefore, placed in median engagement with the stump.
U.S. Pat. No. 5,405,405 (Love) issued on Apr. 11, 1995 for an invention entitled PROSTHETIC SOCKET CONTAINING INFLATABLE MEANS. That reference teaches a composite socket member for use with a prosthetic appliance. An outer socket of the device defines an inner cavity generally conforming to the outer surface of the residual limb of the amputee. An inner socket defines an inner cavity which is intended to receive the amputee's residual limb. The inner socket conforms to the shape of the outer socket and, when nested within the cavity of the outer socket, defines an air space between the inner surface of the outer socket and the outer surface of the inner socket. An inflatable bladder is disposed between the inner surface of the outer socket and the outer surface of the inner socket. Means are provided for inflation of the bladder. The movement and rotation stability of the prosthetic appliance is, thereby, controlled.
U.S. Pat. No. 5,387,245 (Fay et al.) issued on Feb. 7, 1995 for a device characterized as an INFLATABLE PROSTHESIS LINER. The apparatus includes a socket having selectively inflatable bladders which enable the prosthesis to be customized to fit an individual patient. A liner having two liner parts is employed to accomplish this goal. One liner part is placed onto the amputee's stump. A prosthetist then determines the region or regions where bladders are needed to provide a comfortable fit. These areas are identified and overlain with an adhesive. The outer liner is then brought into overlying relationship to the inner liner so that the two liner parts adhere to one another along the outlined regions. After inflation of a bladder or bladders, the inner liner conforms to the stump, and the outer liner conforms to the shape of the inner wall of the socket of the appliance. The device can include an annular bladder at the proximal rim of the socket to create a seal in order to maintain a suction within the socket.
U.S. Pat. No. 5,314,497 (Fay et al.) issued on May 24, 1994 for a device characterized as APPARATUS AND METHOD FOR SEALING A LINER TO A PROSTHESIS. The liner of that reference is intended to cushion an amputee's stump when it is placed into a prosthesis socket. In order to accomplish this, the liner includes selectively inflatable bladders or customizing the liner to fit individual patients. The liner is made of two parts. The first is an inner liner and the second is an outer liner. A region or regions where inflation to expand the space between the two liners might be needed are defined and outlined with an adhesive. The inner and outer liner portions adhere to one another along the outlined regions to define bladders. The bladders can then be selectively inflated to conform the outer liner to the shape of the interior wall of the appliance socket.
U.S. Pat. No. 5,246,464 (Sabolich) issued on Sep. 21, 1993 for an apparatus characterized as ARTIFICIAL LIMB WITH ANATOMICALLY CONFIGURED SOCKET. The device of that reference includes a system of inflatable compartments to enable the adjusting of the size and fit of the prosthesis. With the provision of these compartments, the patient may adjust the dimensions of the socket by inflating one or more of the compartments.
U.S. Pat. No. 5,139,523 (Paton et al.) issued on Aug. 18, 1992 for an ARTIFICIAL LIMB SOCKET APPARATUS. The device disclosed by that reference includes a vent provided through a sleeve support for venting the interior of the socket. The reference also teaches the provision of pneumatic chambers to enhance comfort of the amputee.
U.S. Pat. No. 5,133,776 (Crowder) issued on Jul. 28, 1992. The apparatus of that reference is characterized as a PROSTHETIC VOLUME COMPENSATION DEVICE. It includes an air cell or cells which may be placed into an existing prosthesis or included into a newly-fabricated prosthesis. Means are included to allow for manual adjustment of the degree of inflation of the air cell or cells so that changes in volume of the residual limb of the amputee may be compensated for as required. Inflation is accomplished by a fingertip operated pump. A valve is also provided to allow for exhausting air from the air cell.
U.S. Pat. No. 5,108,456 (Coonan, III) issued on Apr. 28, 1992 for a PROSTHETIC APPLIANCE. That appliance includes several inflatable bladders which, when inflated, act against the rigid side walls of the prosthesis member in order to force portions of the socket member side walls inwardly to grip the residual limb of the amputee. Inflation control means are provided and can include a manually-operable air pump. One or more manually-operable air valves are also provided. A valve is used in combination with each of the bladders to allow for exhaust of air from the corresponding bladder.
U.S. Pat. No. 4,923,475 (Gosthnian et al.) issued on May 8, 1990. The device of that reference is characterized as an INFLATABLE LIMB PROSTHESIS WITH PREFORMED INNER SURFACE. The reference teaches a stump-receiving socket and a plurality of inflatable bladders. Means are employed in order to enable one to vary the pressures within the bladders. The bladders are made of a relatively soft, flexible membrane material such as polyurethane. The membranes are located adjacent the weight-bearing portions of the stump to provide a relatively soft, uniform surface to support the stump. The various pressures in the bladders are independent of each other, and regulation by the user is envisioned.
U.S. Pat. No. 4,655,779 (janowiak) issued on Apr. 7, 1987 for an AIR SYSTEM PROSTHESIS FOR AMPUTEES. The system invention includes a hollow body with stiff peripheral walls and an open end and a cup-shaped partition defining, with the walls, a first socket. The system also includes a second socket having stiff peripheral walls, the second socket being snugly nested within the first socket. The second socket includes spaced apart inner and outer walls with cup-shaped closed ends interconnected and hermetically sealed at their outer ends. A continuous air chamber between the inner and outer walls is, thereby, defined. A manually-operated air pump and pressure relief valve are mounted on the outer wall. Pressurized air can, thereby, be selectively introduced into the chamber and selectively exhausted therefrom.
U.S. Pat. No. 4,432,101 (Johnson) issued on Feb. 21, 1984 for a CUSHIONING PATELLAR SUPPORT DEVICE. The device of that reference includes an inflatable/deflatable bag which is insertable in an upper front portion of a prosthesis. A quick disconnect, hand-operable pump enables the user of the prosthesis to adjust the degree of bag inflation.
U.S. Pat. No. 3,889,301 (Bonner, Sr.) issued on Jun. 17, 1975 for a THERAPEUTIC STUMP TREATING AIR SAC PROSTHESIS. An air sac is provided to surround the amputee's leg stump. The sac, in turn, is surrounded by a casing which confines the pressure of the air sac inwardly against the stump. The distal end of the air sac is supported around and beneath the patient's stump. Means, between the air sac and the casing, are provided to distort the surface of the air sac and give it vertical stability with respect to supporting means.
A foot or partial leg prosthetic includes an artificial limb portion to simulate the natural limb of the amputee which has been removed. The prosthetic does, however, also include means for mating the artificial limb portion to the residual limb of the amputee.
In accomplishing this function, it is important to consider comfort of the prosthetic user. In fact, in many cases, the issue is not only comfort, but also minimization of irritation to the stump. Where the amputee is a diabetic, rubbing can create a blister and infection which could lead to the need for further amputations or, in the extreme case, even death. Also, a liner must provide a friendly, pressure-free environment. Otherwise, the stump fluid will be pressurized and cause skin and tissue inflammation.
As will be able to be seen in view of this discussion, a prosthesis liner in accordance with the present invention has significant advantages over prior art liners. Problems with custom-fitted liners in the prior art, however, are that they are costly and time consuming to measure, assemble, and properly fit such an appliance. It is common to make one or more molds of the amputee's stump in the process. Drying and curing of the mold can consume significant portions of time and result in significant delays.
Another problem is a lack of volume adjustment to the liner cavity. In the case of both custom-fitted liners and pre-made liners in the prior art, there is no ability to adjust for expansion or shrinkage of stump volume.
It is to the shortcomings of the prior art as represented by the references discussed hereinbefore and to advantageous dictates of the art that the present invention is directed. It is an improved prosthetic liner which serves to solve many of the problems of the prior art and which considers the positive dictates suggested by the prior art.